Aromatic Photo-oxidation, A New Source of Atmospheric Acidity
- Sainan Wang*Sainan Wang*Email: [email protected]State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, ChinaMore by Sainan Wang,
- Mike J. NewlandMike J. NewlandWolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, U.K.More by Mike J. Newland,
- Wei DengWei DengState Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, ChinaMore by Wei Deng,
- Andrew R. RickardAndrew R. RickardWolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, U.K.National Centre for Atmospheric Science, Wolfson Atmospheric Chemistry Laboratories, University of York, York YO10 5DD, U.K.More by Andrew R. Rickard,
- Jacqueline F. HamiltonJacqueline F. HamiltonWolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, U.K.More by Jacqueline F. Hamilton,
- Amalia MuñozAmalia MuñozFundación CEAM, EUPHORE Laboratories, Avda. Charles R. Darwin. Parque Tecnológico, Paterna, Valencia, SpainMore by Amalia Muñoz,
- Milagros RódenasMilagros RódenasFundación CEAM, EUPHORE Laboratories, Avda. Charles R. Darwin. Parque Tecnológico, Paterna, Valencia, SpainMore by Milagros Ródenas,
- Monica M. VázquezMonica M. VázquezFundación CEAM, EUPHORE Laboratories, Avda. Charles R. Darwin. Parque Tecnológico, Paterna, Valencia, SpainMore by Monica M. Vázquez,
- Liming WangLiming WangSchool of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou, ChinaMore by Liming Wang, and
- Xinming Wang*Xinming Wang*Email: [email protected]State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, ChinaMore by Xinming Wang
Abstract
Formic acid (HCOOH), one of the most important and ubiquitous organic acids in the Earth’s atmosphere, contributes substantially to atmospheric acidity and affects pH-dependent reactions in the aqueous phase. However, based on the current mechanistic understanding, even the most advanced chemical models significantly underestimate the HCOOH concentrations when compared to ambient observations at both ground-level and high altitude, thus underrating its atmospheric impact. Here we reveal new chemical pathways to HCOOH formation from reactions of both O3 and OH with ketene-enols, which are important and to date undiscovered intermediates produced in the photo-oxidation of aromatics and furans. We highlight that the estimated yields of HCOOH from ketene-enol oxidation are up to 60% in polluted urban areas and greater than 30% even in the continental background. Our theoretical calculations are further supported by a chamber experiment evaluation. Considering that aromatic compounds are highly reactive and contribute ca. 10% to global nonmethane hydrocarbon emissions and 20% in urban areas, the new oxidation pathways presented here should help to narrow the budget gap of HCOOH and other small organic acids and can be relevant in any environment with high aromatic emissions, including urban areas and biomass burning plumes.
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This article is cited by 2 publications.
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